This disclosure relates generally to a tool for removal of a broken bolt, and more particularly to a broken bolt extractor for removing a portion of a threaded fastener that remains lodged in a threaded bore.
Bolts, such as bolts having sizes M8 to M14, have a bolt head and a threaded bolt stud or body. Due to the construction of a bolt, the bolt head may become separated or break off from the threaded bolt stud when attempting to remove the bolt. If this occurs then separation of the bolt head from the stud will leave the stud or a portion of a stud in a threaded bolt bore. Removing the broken bolt or stud is a cumbersome and difficult process. There have been several devices or methods developed in an effort to assist in removing the broken bolt. For example, one prior device requires that a separate drill bit be used to drill a hole in the stud. Once a hole is drill to a sufficient depth in the stud a second tool is used to be inserted into the drilled hole to extract the stud portion from the bore within which the stud portion is lodged or stuck. One problem associated with this process is that the drill bit breaks during the drilling process and becomes lodged in the stud. Instead of solving a problem another problem is encountered in that now the broken drill bit needs to be removed. Further, using a separate drill bit sometimes will rotate the stud body deeper into the threaded bore. This makes removal of the broken bolt stud even more difficult. Another prior device combines a drill bit with a bolt stud extractor in a single tool. However, this prior device requires that the bolt stud extractor be placed on a threaded tool shaft and the bolt stud extractor rotates during use until it becomes lodged in the stud to be extracted. One problem associated with this use of this device is that it is capable of coming off the threaded tool shaft during use. If this occurs, then the problem of having to remove the bolt stud extractor lodged in the stud body is encountered. Again, not only is the broken bolt not removed but the broken tool now has to be removed. It would be desirable to avoid encountering a situation in which the tool is required to be extracted from the broken bolt. Further, the drill bit portion of this device is very small and may not drive deep enough into the broken bolt section for the extractor to grip enough of the broken bolt section.
The present disclosure is designed to obviate and overcome many of the disadvantages and shortcomings experienced with prior bolt extractors. Moreover, the present disclosure is related to a broken bolt extractor that can be easily manipulated or employed to remove broken bolts of various sizes. The broken bolt extractor of the present disclosure is also simple to use due to the extractor only being a single tool or device that does not require any moving parts attached to the extractor.